Mar 31 2022

Dowsing for Bodies

Dowsing is one of those pseudosciences that proves James Randi’s aphorism that such cons are often like “unsinkable rubber ducks” – no matter how often you push them down, they keep coming back. Here is yet another story of a scientist falling for dowsing and spreading this nonsense to students, law enforcement, and even in the courtroom. Arpad Voss is a forensic scientist with a PhD in anthropology. He is now the latest cautionary tale demonstrating that being a legitimate scientist is not in itself protection from also falling for pseudoscience.

He follows a long pedigree of such cautionary tales – two-time Nobel Laureate Linus Pauling, who was a brilliant chemist but not a doctor, convinced himself that high doses of Vitamin C was a powerful cure. Luc Montagnier, also a Nobel Laureate for his work on discovering HIV, fell for one of the rankest of medical pseudosciences, homeopathy. Psychologists Targ and Puthoff famously fell for an ESP scam, unable to leverage their scientific chops to detect the deception. Neuroscience researcher Steven Laureys fell for facilitated communication, because he was simply unfamiliar with the phenomenon.

It happens over and over again – scientists assume that being an accomplished scientist shields them from self-deception and pseudoscience. It doesn’t, for at least two very good reasons. First, the practice of science involves at least two general types of knowledge. There is technical/factual knowledge, the ability to carry out an experiment, to perform statistical analysis, operate technical machinery, and specific topic expertise. But there is also philosophical/critical thinking knowledge, understanding the underlying philosophy of science, mechanisms of deception, and how science can be perverted and slide into pseudoscience. The world is full of people who have the former skill sets but lack the latter. This is why, for example, creationist Duane Gish was able to go around the country debating evolutionary scientists and get the rhetorical better of them. The scientists naively thought they only needed to understand the science of evolution, but really they also needed to understand the pseudoscience of creationism.

Now we have a forensic scientist who thinks that dowsing works. Voss, by all accounts, is an accomplished and well-trained forensic scientist. However, there is a hint in his history that while he may be accomplished in the technical realm he is lacking in the critical thinking realm. He has been developing a database of “decomposition odor analysis”, or “DOA”, which lists over 400 chemicals released by a decomposing body. He testified in the murder trial of Casey Anthony, who was accused of killing her three-year old daughter. Voss testified that he could detect decomposition molecules in the trunk of her car, but his testimony was countered by other experts who pointed out that same molecules could result from plastic or food (like groceries one might put in the trunk of their car). Anthony was acquitted and Voss’s reputation took a hit, and Voss himself says it lead to him losing his job.

Forensic science is an applied science and a very important one. People’s lives hang in the balance of the testimony of forensic experts. In medicine we have a “first do no harm” principle. Forensic science should have something similar – don’t overcall results, don’t overstate your confidence or downplay doubt. Recently many forensic science techniques have been called out for being less than rigorous, and for experts overcalling their accuracy, including finger print analysis, blood splatter analysis, fiber analysis, and bite-mark analysis. This is ultimately a good thing – forensic science appears to need a revolution in which much higher levels of scientific rigor are required for evidence to be used in court. Many think the overreliance of forensic science is partly a result of all the CSI-type TV shows that hype the techniques.

Enter into this context, Voss using dowsing to find bodies, and teaching these techniques to forensic students. Dowsing, in case you need reminding, is the superstition of using some technique, usually two dowsing rods, to detect something, traditionally underground water. The classic technique is to hold two L-shapes rods, one in each hand, so they point outward then wander around looking for whatever. When you get to the target, the rods spontaneously move and cross over each other, indicating you have hit your goal. It is now well-established that the rods move because the person holding the rods makes them move. This is a phenomenon known as the ideomotor effect, and is responsible for things like how a Ouiji board works. Dowsing has also been tested to death – it simply does not work. If the dowser is properly blinded to the target, they cannot detect anything.

Voss, when confronted with this reality, goes full pseudoscienst (which of course, as you know, you should never do). He compares himself to Galileo. He also says the scientists testing dowsing don’t really understand it, and its “17 scientific principles” that he alone understands. This is the same special pleading that all cranks give when rigorous science disproves their claims. He claims that dowsing through bones works through detecting the piezoelectric effect. This, of course, is nonsense – bones can produce a piezoelectric effect, a small electric current, when under strain. That is how bones remodel to conform to the stress that they are under, and how braces straighten your teeth. But this electric current is tiny. You cannot detect it through the ground, even with proper instruments, let alone a couple of magical rods.

This is just another sad chapter marring the reputation of the investigative and forensic professions. They really do need to get their stuff together, weed pseudoscience out of their profession, and have a zero-pseudoscience policy. They have a responsibility not to ruin people’s lives because of their own intellectual laziness or lack of professional rigor. Further, they are giving a gift to defense attorneys. Voss or any student of Voss who uses dowsing in their work can now have their testimony called into question on the witness stand – and with good reason. I know every profession has this problem, including my own profession of medicine (which is why I have dedicated so much effort to opposing it). Forensic science needs to purge the pseudoscience from their ranks.

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